FIELD OF INVENTION
[001] The present invention relates generally to the field of batteries and specifically relates to
system and methods for temperature regulations in battery pack system comprising plurality
of battery cells.
BACKGROUND
[002] A battery pack system includes multiple modules comprising plurality of battery cells.
Battery pack systems are widely used in various power storage devices, vehicles, etc. Vehicles
using electric power for all or a portion of their motive power (e.g., Battery electric vehicles
(BEVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and the
like, collectively referred to as “electric vehicles”), may provide a number of advantages as
compared to more traditional gas-powered vehicles using internal combustion engines. Over
the rising concerns of oil costs, climate change and energy security, efforts to promote energy
efficient electric vehicles have grown. Energy efficient electric vehicles provide overall
reduced air emissions compared to conventional combustion vehicles.
[003] The performance of power storage devices and electric vehicles depend on a battery pack
system. It is known that temperature has an influence over life and safety of a battery pack
system. For power storage and electric vehicle applications, a battery pack system experiences
high charge and discharge rates and the internal chemical reactions of the battery cell generates
heat.

[004] The battery pack system needs to be charged and discharged at a suitable temperature range to minimize the battery cell life degradation. Thus, it becomes necessary to precondition the battery pack system before charging and discharging.
[005] Thus, a thermal management system for a battery pack system is required to keep the battery cell temperature within an optimum range to achieve desired performance in varied climate conditions before and during charging as well as discharging the battery pack system.
[006] The battery cells are closely arranged in the battery modules to get maximum packing efficiency and are electrically connected in series or parallel. Existing battery pack systems comprise of heat conducting tubes in contact with side surfaces of the battery cells. These heat conducting tubes pass through narrow gaps between rows of cells. Such system requires labor and cost intensive method for assembling the battery pack system, which increases the cost of the system. The present invention provides a battery pack system overcoming the need for special assembly methods, thus reducing the cost.
BRIEF DESCRIPTION
[007] This summary is provided to introduce a selection of concepts in a simple manner that are
further described in the detailed description of the disclosure. This summary is not intended to
identify key or essential inventive concepts of the subject matter nor is it intended for
determining the scope of the disclosure.
[008] In one embodiment, a battery pack system is disclosed. The battery pack system comprises
at least one battery module having at least one battery cell and supported by at least one
supporting structure. Further, the battery pack system provides an inlet for coolant entrance
into the battery pack system, the inlet is coupled to at least one coolant compartment.
Furthermore, an outlet for coolant exit from the battery pack system is provided, the outlet is

coupled to at least one coolant compartment, wherein the coolant compartment is coupled to at least one inner and at least one outer tube. A thermally conductive and electrically insulative (TCEI) material is provided and is configured to contact an outer wall of at least one outer tube and an outer wall of at least one of the battery cell such that the TCEI material transfers the heat between the one or more battery cells and the one or more outer tubes.
[009] The battery cells are electrically connected according to the voltage and current requirements from the battery pack system and any number of such electrical connections are possible.
[0010] In accordance with second embodiment of the present invention, a method for maintaining uniform and equal temperatures of all battery cells is provided.
[0011] In accordance with third embodiment of the present invention, a thermal management system is provided for the heating and cooling of the battery pack system.
BRIEF DESCRIPTION OF DRAWINGS
[0012] Embodiments of the disclosure will now be described, by way of example, with reference
to the accompanying drawings, in which: [0013] Fig. 1(a) is a perspective view of the battery pack system, in accordance with the first
embodiment of the present invention. [0014] Fig. 1(b) is a perspective view of internal structure of the battery pack system, in
accordance with the first embodiment of the present invention. [0015] Fig. 1(c) is a perspective view of internal structure of the battery pack system excluding
battery modules, in accordance with the first embodiment of the present invention.

[0016] Fig. 1(d) is a sectioned perspective view of internal structure of the battery pack system
emphasizing top coolant compartment, in accordance with the first embodiment of the present
invention. [0017] Fig. 1(e) is a sectioned perspective view of internal structure of the battery pack system
emphasizing bottom coolant compartment, in accordance with the first embodiment of the
present invention. [0018] Fig. 1(f) is a section view of the battery pack system showing coolant flow in counter¬clockwise direction, in accordance to the second embodiment to the present invention. [0019] Fig. 1(g) is a section view of the battery pack system showing coolant flow in clockwise
direction, in accordance to the second embodiment to the present invention. [0020] Fig. 2(a) is a cross section view of the battery cells in a square arrangement having a
circular inner tube and a star shaped outer tube with thermally conductive electrically insulative
(TCEI) material on outer walls of the outer tube. [0021] Fig. 2(b) is a cross section view of the battery cells in a triangular arrangement having a
circular inner tube and a star shape outer tube with TCEI material on outer walls of the outer
tube. [0022] Fig. 2(c) is a cross section view of the battery cells in a hexagonal arrangement having a
circular inner tube and a star shape outer tube with TCEI material on outer walls of the outer
tube. [0023] Fig. 2(d) is a cross section view of the battery cells in a hexagonal arrangement having a
hexagonal inner tube and a hexagonal outer tube with TCEI material on outer walls of the outer
tube.

[0024] Fig. 2(e) is a cross section view of the battery cells in a hexagonal arrangement having a circular inner tube and a circular outer tube with TCEI material on outer walls of the outer tube.
[0025] Fig. 2(f) is a cross section view of the battery cells in a square arrangement having two inner tubes and a star shape outer tube with TCEI material on outer walls of the outer tube.
[0026] Fig. 2(g) is a cross section view of the battery cells in a hexagonal arrangement having four sections in inner tube and a star shape outer tube with TCEI material on outer walls of the outer tube.
[0027] Fig. 2(h) is a cross section view of the battery cells in a square arrangement having circular inner tube and a circular outer tube with TCEI material on outer walls of the battery cells.
[0028] Fig. 3 is a schematic of the battery system with a thermal management system, in accordance with the third embodiment of the present invention.
[0029] Further, persons skilled in the art to which this disclosure belongs will appreciate that elements in the figures are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the figures with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
DETAILED DESCRIPTION
[0030] For the purpose of promoting an understanding of the principles of the disclosure, reference
will now be made to the embodiment illustrated in the figures and specific language will be
used to describe them. It will nevertheless be understood that no limitation of the scope of the

disclosure is thereby intended. Such alterations and further modifications to the disclosure, and such further applications of the principles of the disclosure as described herein being contemplated as would normally occur to one skilled in the art to which the disclosure relates are deemed to be a part of this disclosure.
[0031] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the disclosure and are not intended to be restrictive thereof.
[0032] The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such a process or a method. Similarly, one or more devices or sub-systems or elements or structures or components preceded by "comprises... a" does not, without more constraints, preclude the existence of other devices, other subsystems, other elements, other structures, other components, additional devices, additional sub-systems, additional elements, additional structures, or additional components. Appearances of the phrase “in an embodiment”, “in another embodiment” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.
[0034] Embodiments of the present disclosure will be described below in detail with reference to the accompanying figures.

[0035] For exemplary and simplicity purpose, the present disclosure and the corresponding drawings explain a battery pack system comprising “cylindrical battery cells”. However, it is to be noted that the various embodiments of the present disclosure are applicable for battery cells having different geometries in the battery pack system. Other types of battery cell geometries include prismatic cell geometry, pouch cell geometry, etc.
[0036] Referring to Fig.1(a), Fig.1(b), Fig.1(c), Fig.1(d) and Fig.1(e) a battery pack system 100 provided for the temperature regulation of the battery cells 141 comprises of two battery modules 140 is disclosed. As used herein, a battery module is a group of electrically connected battery cells arranged together with supporting structure. Each battery module 140 comprises of battery cells 141 arranged adjacent to each other held together with the supporting structures 142. The battery casing 130 encloses and holds the battery modules 140 together. One or more such battery modules constitute the battery pack system 100.
[0037] The present invention does not intend to limit the number of battery modules 140 in a battery pack system 100. One or more battery modules 140 may be used by extending the casing structure 130 of the battery pack system 100. The battery modules 140 may be arranged upon one another or adjacent to each other, i.e. in a horizontal or a vertical structure.
[0038] The arrangement pattern of the battery cells 140 may be staggered or inline. Moreover, the battery cells may be in a triangular, square, pentagonal, hexagonal arrangement or any possible geometry. The present invention does not intend to limit the arrangement pattern of the battery cells 141 inside the battery modules 140 or the arrangement of the battery modules 140 inside the casing 130.
[0039] Further, the battery pack system 100 comprise openings for coolant to flow in and out of the system. The openings are now onwards referred to as “inlet-outlet pair”. The inlet-outlet

pair is numbered 111 and 112. The battery pack system 100 further comprises of a container 120, wherein the container 120 is coupled to the inlet-outlet pair 111 and 112, wherein the container is further coupled to tubes 150. The tubes 150 are in contact with thermally conductive electrically insulative (TCEI) material 160. The TCEI material 160 thermally connects the tubes 150 to the battery cells 141. The TCEI material prevents any electrical contact of the battery cells 141 with the tubes 150 while allows the heat to be conducted between the battery cells 141 and the tubes 150. The TCEI material may be silicone rubbers, thermal epoxies, thermal foam or other such materials known in the art.
[0040] Coolant having lower temperature than battery cell 141 temperature is supplied for cooling the battery cell 141. Herein, the TCEI material 160 absorbs the heat from the battery cells 141 and discharges it to the tubes 150, such that the heat from the tubes 150 is taken away from the cold coolant. Similarly, when heating of the battery cell 141 is required, coolant having higher temperature than battery cell 141 is supplied. Herein, the TCEI material 160 discharges the heat to the battery cells 141 from the tubes 150, the tubes 150 are heated by the hot coolant.
[0041] As illustrated in Fig.1(d) and Fig.1(e), the container 120 is divided into compartments 121 and 122. As illustrated in Fig.1(f), the tube 150 has an inner tube 151 and an outer tube 152. The compartment 121 is coupled to the inner tube 151 and the compartment 122 is coupled to outer tube 152 respectively.
[0042] The coolant is circulated inside the battery structure using at least one of the two methods - clockwise and counter-clockwise. In the first method, as illustrated in Fig.1(f), 112 acts as a coolant inlet for battery pack system 100 and the coolant gets distributed from the compartment 122 to the outer tubes 152. The coolant gets channelized into the inner tube 151. The compartment 121 collects the coolant from the tubes 151 and directs it to the outlet 111. The

coolant absorbs heat from the battery modules which are placed above and then from the battery modules which are placed below. Thus, the temperature of the battery cells 141 in the lower module becomes higher than the temperature of the battery cells in the upper module.
[0043] In the second method of coolant circulation, as illustrated in Fig.1(g), 111 acts as a coolant inlet for the battery pack system 100 and the coolant gets distributed from the compartment 121 to the inner tubes 151. The coolant gets channelized into the outer tube 152. The compartment 122 collects the coolant from the tubes 152 and directs it to the outlet 112. The coolant absorbs heat from the battery modules which are placed below and then from the battery modules which are placed above. Thus, the temperature of the battery cells 141 in the upper module becomes higher than the temperature of the battery cells in the lower module.
[0044] Referring to Fig. 1f- 1g, in accordance with the second embodiment of the present disclosure, a method for maintaining uniform and equal temperatures of all battery cells 141 by to and fro flow of coolant is provided. Uniform and equal temperatures of the battery cells 141 is achieved by reversing the flow of coolant at regular time intervals and make it flow clockwise and counter-clockwise as described in paragraphs [0042] & [0043]. The time interval cycles for the flow of coolant in and out of the battery pack system may be predetermined by a controller or manually set by an operator and may change according to conditions.
[0045] The battery cell 241 may be arranged in different arrangements along with tube 250 and TCEI material 260. Moreover, the geometries of inner tube 251 and outer tube 252 may be of any possible shape. Moreover, TCEI 260 may be attached on outer walls of the outer tubes 150 or outer walls of the battery cells 241. Also, TCEI 260 may be of any possible shape as long as it facilitates heat conduction between the battery cells 241 and tubes 250.

[0046] As illustrated in Fig. 2(a), one arrangement of the battery cells 241 with tubes 250 and TCEI 260 is shown. The battery cells 241 are arranged in a square arrangement having a circular inner tube 251 and a star shaped outer tube 252 with TCEI material 260 on outer walls of outer tube 252. Another possible square arrangement of the battery cells 241 is shown in Fig. 2(f), but with two inner tubes 251.
[0047] As illustrated in Fig. 2(b), another arrangement of the battery cells 241 with tubes 250 and TCEI 260 is shown. The battery cells 241 are arranged in a triangular arrangement having a circular inner tube 251 and a star shape outer tube 252 with TCEI material 260 on outer walls of outer tube 252.
[0048] As illustrated in Fig. 2(c), another possible arrangement of the battery cells 241 with tubes 250 and TCEI 260 is shown. The battery cells 241 are arranged in a hexagonal arrangement having a circular inner tube 251 and a star shape outer tube 252 with TCEI material 260 on outer walls of outer tube 252 is shown. Another possible hexagonal arrangement of the battery cells 241 is shown in Fig. 2(d) but with a hexagonal shaped inner 251 and outer tubes 252. Another possible hexagonal arrangement of the battery cells 241 is shown in Fig. 2(e) but with circular inner 251 and outer tubes 252. The hexagonal arrangement shown in Fig. 2(g) shows inner tube 251 has four sections.
[0049] As illustrated in Fig. 2(h), yet another arrangement of the battery cells 241 with tubes 250 and TCEI material 260 is shown. The battery cells 241 are arranged in a square arrangement having a circular inner tube 251 and a circular outer tube 252 with TCEI material 260 on outer walls of the battery cell 241 is shown.
[0050] In accordance with the third embodiment of the present invention, a thermal management system 300 is provided for the battery pack system as illustrated in Fig.3. The thermal

management system 300 comprises of a battery pack system 370, a heater 372, a pump 373, a heat exchanger 374, a two-way valve 375, and a coolant reservoir 371. Piping connections and the coolant is not shown in the illustration.
[0051] The present disclosure does not intend to limit the type and quantity of components mentioned in the previous section. For example, the heat exchanger 374 may be either of an air cooled radiator, liquid to liquid heat exchanger, etc. Similarly, the pump 373, the valve 375, the heater 372, and the coolant reservoir 371 may be of different types. The coolant used may be of any type and either in liquid or gaseous state.
[0052] If multiple battery pack systems 370 are used, these battery pack systems 370 may be thermally connected in series or parallel. But connecting the battery pack systems 370 in parallel gives an advantage of having equal battery pack system temperatures. One or more pumps 373, heaters 372, heat exchangers 374, valves 375 and reservoirs 371 may be connected in any possible combination; but, that would result in a less efficient system as compared to using single components. Moreover, the order of components may be different than illustrated.
[0053] The thermal management system 300 operates in accordance to the climate conditions. For example, if the outside temperature is higher than 40 degree Celsius, the battery cells inside the battery pack system 370 may be at higher temperature than the desired operating temperature. Thus, it becomes necessary to lower the battery cell temperature to a desired level before operation. The two-way valve 375 diverts the coolant flow through heat exchanger 374 and the heater 372 is switched off. Thus, the heat from battery cell in the battery pack system 370 is absorbed by the coolant and is discharged to the heat exchanger 374. Once the desired operating temperature of the battery cells is achieved, the battery pack system 370 is allowed to operate and the coolant continues to flow through the heat exchanger 374 to dissipate heat

generated from the operation of battery pack system 370. The flow rate of the pump 373 is adjusted to maintain the desired operating temperature of the battery pack system 370. [0054] The switching and control operations of the two-way valve 375, the heater 372, or the pump
373 may be controlled by a controller or may be manually set by an operator.
[0055] For example, if the outside temperature is lower than 10 degree Celsius, the battery cell inside the battery pack system 370 may be at lower temperature than the desired operating temperature. Thus, it becomes necessary to raise the battery cell temperature to a desired level before operation. The two-way valve 375 diverts the coolant flow to bypass the heat exchanger
374 and the heater 372 is switched on. The heating of the battery cells is obtained. Once the
desired operating temperature is achieved, the heater 372 is switched off and the battery pack
system 370 is allowed to operate. Now, the two-way valve 375 diverts the coolant flow through
the heat exchanger 374 to dissipate heat generated from the operation of battery pack system
370. The flow rate of the pump 373 is adjusted to maintain the desired operating temperature
of the battery pack system 100.
[0056] The battery pack system 100 of the present disclosure, provides an efficient and cost effective mechanism for thermal regulation. Moreover, the control method as disclosed in the foregoing description is comparatively less labor intensive, thereby reducing the power consumption.
[0057] While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person skilled in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.

[0058] The figures and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of embodiments is at least as broad as given by the following claims.

WE CLAIM
1. A battery pack system 100 comprising:
at least one battery module 140, comprising at least one battery cell 141;
at least one supporting structure 142, configured for providing structural support to at
least one battery cells 141;
an inlet 111 for coolant entrance into the battery pack system 100, the inlet 111 coupled
to at least one coolant compartment 121, wherein the coolant compartment 121 is
coupled to at least one inner tube 151;
an outlet 112 for coolant exit from the battery pack system 100, the outlet 112 is coupled
to at least one coolant compartment 122, wherein the coolant compartment 122 is
coupled to at least one outer tube 152;
a TCEI material 160 configured to contact at least an outer wall of at least one outer
tube 152 and an outer wall of at least one of the battery cell 141 such that the TCEI
material 160 transfers the heat between the one or more battery cells 141 and the one or
more outer tubes 152.
2. The battery pack system 100 as claimed in claim 1, wherein the inner tube 151 is made up of a thermally non-conductive or less conductive material.
3. The battery pack system 100 as claimed in claim 1, wherein the outer tube 152 is made up of a thermally conductive material.
4. The battery pack system 100 as claimed in claim 1, wherein the battery cells 141 are arranged in a triangular, a rectangular, a pentagonal, a hexagonal, a heptagonal, a

octagonal or a circular arrangement.
5. The battery pack system 100 as claimed in claim 1, wherein the battery cells 141 are arranged in a staggered or inline arrangement.
6. The battery pack system 100 as claimed in claim 1, wherein the battery modules 140 are arranged adjacent to each other.
7. The battery pack system 100 as claimed in claim 1, wherein the battery modules 140 are stacked upon one another.
8. The battery pack system 100 as claimed in claim 1, wherein inner tubes 151 has multiple sections in it.
9. The battery pack system 100 as claimed in claim 1, wherein the TCEI materials 160 has more than one layers.
10. The battery pack system 100 as claimed in claim 1, wherein one or more outer tubes 152 are used each having at least one inner tube 151 in it, wherein these outer tubes 152 are enclosed in at least one TCEI material 160.
11. The battery pack system 100 as claimed in claim 1, wherein the circulation of the coolant in the battery pack system is in one of a clockwise and anti-clockwise direction for a predetermined time period.

12. A thermal management system 300 for the temperature regulation of the battery pack system 370 as claimed in claim 1 comprising:
at least one battery pack system 370, wherein the battery pack system 370 is
operatively coupled to at least one heat exchanger 374;
a pump 373, the pump 373 is operatively coupled to a heater 372, the heater 372 is
operatively coupled to a reservoir 371, wherein the reservoir 371 is operatively
coupled to the battery pack system 370;
a coolant, wherein the coolant is used for heat transfer between the battery pack
system 370, the heater 372 and the heat exchanger 374, the coolant is filled into the
system 300 through the reservoir 371;
a two-way valve 375, the two-way valve 375 is operatively coupled to the heat
exchanger 374, wherein the two-way valve 375 is used for letting the coolant flow
through the heat exchanger 374 or bypassing the heat exchanger 374.